1911Forum - View Single Post - Hey Steve! (in Allentown), What about 9's & 10's?
View Single Post
  #16  
Old 01-22-2020, 03:38 PM
Steve in Allentown Steve in Allentown is offline
Member
 
Join Date: Sep 2010
Location: Allentown, PA
Posts: 1,800
Quote:
Originally Posted by Jolly Rogers View Post
Why would case length matter? Rim thickness from base to extractor grove should be the determining factor.
Joe
Here are the optimum hook-to-breechface distances provided by log man:
  • 9mm - .060"
  • 40 S&W - .065"
  • 45 ACP - .075"

Here are the SAAMI specs for rim thickness from base to extractor groove:
  • 9mm - .050"
  • 40 S&W - .055"
  • 45 ACP - .049"

I'm not seeing the correlation between rim thickness and hook-to-breechface distances. That distance may be more of a function of the angle at which the rim begins moving up behind the extractor. That angle would be influenced by the length of the cartridge. I'm just speculating here. Where are the engineers when you need them?
Reply With Quote